College of Life Science, Northeast Forestry University, Harbin, Heilongjiang, China.
College of Life Science, Northeast Forestry University, Harbin, Heilongjiang, China.
J Hazard Mater. 2022 Feb 15;424(Pt A):127265. doi: 10.1016/j.jhazmat.2021.127265. Epub 2021 Sep 20.
Nitrogen dioxide (NO) is a common outdoor air pollutant, which has adverse effects on the environment and human health. Herein, NO inhibited photosynthesis and antioxidant capacity in plants. Melatonin (Mel) is a neurohormone found in the pineal gland. Exogenous Mel alleviated chlorophyll degradation and increased the expression of key proteins and genes in the process of chlorophyll synthesis in tobacco leaves exposed to NO. Additionally, the activities of photosystem II (PSII) and photosystem I (PSI) were enhanced. PSII and PSI reaction center proteins and genes were upregulated. Mel pre-treatment enhanced enzyme activities and expression of proteins related to the ascorbic acid-glutathione cycle and thioredoxin-peroxiredoxin pathway in leaves exposed to NO, thus regulating their redox balance. Furthermore, exogenous Mel mediated the polyamine synthesis pathway and increased the expression of the key enzyme proteins SAMS1, SAMS2, and SAMS3 in the polyamine synthesis pathway in leaves under NO stress. Mel regulated ABA signal transduction and calmodulin binding transcription factors CAMTA12 and NtCaM calmodulin NtCaM2 in Ca signal transduction. Collectively, these results elucidate that Mel can alleviate high-concentration NO, thus suitable for agricultural application.
二氧化氮（NO）是一种常见的室外空气污染物，对环境和人类健康有不良影响。在此，NO 抑制了植物的光合作用和抗氧化能力。褪黑素（Mel）是一种在松果体中发现的神经激素。外源 Mel 减轻了暴露于 NO 的烟草叶片中叶绿素的降解，并增加了叶绿素合成过程中关键蛋白和基因的表达。此外，提高了光系统 II（PSII）和光系统 I（PSI）的活性。上调了 PSII 和 PSI 反应中心蛋白和基因的表达。Mel 预处理增强了暴露于 NO 的叶片中与抗坏血酸-谷胱甘肽循环和硫氧还蛋白-过氧化物酶途径相关的酶活性和蛋白表达，从而调节其氧化还原平衡。此外，外源 Mel 介导多胺合成途径，并增加了多胺合成途径中关键酶蛋白 SAMS1、SAMS2 和 SAMS3 的表达。Mel 调节 ABA 信号转导和钙信号转导中的钙调蛋白结合转录因子 CAMTA12 和 NtCaM 钙调蛋白 NtCaM2。综上所述，这些结果表明 Mel 可以缓解高浓度 NO，因此适合农业应用。
